Article
Chemistry, Multidisciplinary
Sisheng Duan, Jing-Yang You, Jian Gou, Jie Chen, Yu Li Huang, Meizhuang Liu, Shuo Sun, Yihe Wang, Xiaojiang Yu, Li Wang, Yuan Ping Feng, Yi-yang Sun, Andrew T. S. Wee, Wei Chen
Summary: This study reports the growth of single-layer iron germanide kagome nanoflakes and reveals the electronic localization of the kagome flat bands using scanning tunneling microscopy/spectroscopy. First-principles calculations demonstrate the topological nature and edge mode of the observed kagome materials.
Review
Chemistry, Multidisciplinary
Xiang Wang, Yu-Qi Wang, Ya-Chen Feng, Dong Wang, Li-Jun Wan
Summary: Understanding the mechanism of electrocatalytic reactions is crucial for designing efficient electrocatalysts for energy technology. The use of scanning tunnelling microscopy (STM) has become a powerful tool to investigate surface structures and processes in electrocatalysis, contributing to the development of emerging electrocatalysts. STM has been extensively utilized in electrocatalysis research, providing insights into the structure-activity relationships and surface processes of electrocatalysts.
CHEMICAL SOCIETY REVIEWS
(2021)
Article
Engineering, Electrical & Electronic
Chinedu Christian Ahia, Ngcali Tile, Edson L. Meyer, Johannes Reinhardt Botha
Summary: High resolution X-ray diffraction, scanning probe microscopy, scanning electron microscopy, and optical microscopy were used to evaluate the crystallinity and morphology of epitaxial layers of InSb deposited on GaSb substrate. The study showed that the thickness and quality of the deposited InSb layers are highly sensitive to changes in growth temperatures and V/III ratios, regardless of the Sb source used. Additionally, XRD patterns indicated an improvement in crystallinity for InSb layers deposited using TMSb compared to TDMASb.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Review
Chemistry, Physical
Prachi Ghoderao, Sanjay Sahare, Shern-Long Lee, Prashant Sonar
Summary: Scanning probe microscopy (SPM) is a powerful technique that allows for the observation and analysis of nanoscale materials and biological molecules through the use of sharp probes that scan the sample surface. This method, which includes scanning tunneling microscopy (STM) and atomic force microscopy (AFM), provides valuable insights into the properties and behavior of these materials at a molecular level. This review highlights the applications of SPM in biomolecule imaging and the study of physiological processes, as well as the challenges and potential solutions in biological sample preparation. It also discusses the recent advancements in STM and AFM applications on biomolecules, such as DNA, proteins, and carbohydrates, and their potential applications in fields like drug delivery and biosensors.
Article
Materials Science, Multidisciplinary
Jacob J. Repicky, Brad Goff, Shuyu Cheng, Roland K. Kawakami, Jay A. Gupta
Summary: Magnetic multilayers are a promising platform for storage and logic devices utilizing skyrmion spin textures. In this study, [Pt/Co/Cu]n superlattices were grown by molecular beam epitaxy and characterized using spin-polarized scanning tunneling microscopy (SP-STM). The results show the presence of irregular-shaped skyrmion bubbles with large effective diameters that are larger than the surface grain structure. The motion and manipulation of these skyrmion bubbles were achieved using the stray field of a ferromagnetic tip and spin-polarized current/voltage pulses.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Hesham El-Sherif, Natalie Briggs, Brian Bersch, Minghao Pan, Mahdi Hamidinejad, Siavash Rajabpour, Tobin Filleter, Ki Wook Kim, Joshua Robinson, Nabil D. Bassim
Summary: In this study, the thickness of 2D-Ga heterostructures was resolved and measured using scanning electron microscopy (SEM), with the SEM image contrast directly related to the presence of uniform bilayer Ga at the interface and variation of graphene layers. By utilizing multiple correlative methods, the researchers investigated the origin of SEM contrast and found that a carbon buffer layer detached due to gallium intercalation, increasing the surface potential as an indication of the 2D-Ga presence. The study also successfully scaled up heterostructure characterization over a few-square millimeter area by segmenting SEM images with nanometer-scale in-plane resolution, leveraging the spectroscopic imaging capabilities of SEM for tracking intercalants, identifying relative surface potentials, determining the number of 2D layers, and further characterizing scalability and uniformity of low-dimensional materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Lu'an Guo, Yitao Wang, Dogan Kaya, Zhiming Wang, Min Zhang, Quanmin Guo
Summary: Researchers successfully built a C-60-C-70 organic molecular heterojunction on the HOPG surface using layer-by-layer growth method. C-70 molecules assemble into a close-packed second layer matched to the underlying C-60 layer, showcasing unique physical properties and functionality.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Elie Geagea, Judicael Jeannoutot, Louise Morgenthaler, Simon Lamare, Frank Palmino, Frederic Cherioux
Summary: A new strategy to obtain coordination polymers by transforming supramolecular networks into coordination polymers through surface-assisted cyclo-dehydrogenation of organic building blocks is proposed. All nanostructures were fully characterized using scanning tunneling microscopy under ultra-high vacuum on a gold surface. The balance between molecule-molecule interaction and molecule-substrate interaction can be drastically modified by a strong modification of the geometry of the molecules through thermal annealing, demonstrating an efficient method to elaborate on-surface coordination polymers.
Article
Chemistry, Physical
Oleg Kurnosikov, Muriel Sicot, Emilie Gaudry, Danielle Pierre, Yuan Lu, Stephane Mangin
Summary: A non-destructive method for visualizing and characterizing buried nano-structures under a metal surface using scanning tunnelling microscopy/spectroscopy (STM/STS) has been developed. The method utilizes quantum well (QW) states to single out and access the nano-objects buried under the metal surface. The burial depth of the nano-objects can be determined by analyzing the oscillatory behavior of electron density at the sample surface, while the spatial distribution of electron density provides additional information about their size and shape.
NANOSCALE HORIZONS
(2023)
Article
Chemistry, Multidisciplinary
Song Zhou, Lei Liao, Lan Chen, Baojie Feng, Xiaoyue He, Xuedong Bai, Chuangye Song, Kehui Wu
Summary: This study demonstrates the possibility of maintaining stable in-plane polarization in an extremely thin Bi2WO6 film by using a perfectly lattice-matched NdGaO3 (110) substrate. The residual polarization in this ultrathin film is attributed to the crystal stability of the Bi-O octahedral framework against structural distortions. These findings suggest the potential of the Bi2WO6/NdGaO3 (110) system as a platform for designing low-energy consumption, nonvolatile ferroelectric memories.
Article
Chemistry, Physical
Cesar D. Mendoza, Igor J. Califrer, Fernando L. Freire
Summary: Twisted bilayer graphene was synthesized on a nickel substrate using chemical vapour deposition and studied for Moire superlattice generation caused by misorientation in stacking. Raman spectroscopy and scanning tunnelling microscopy (STM) were utilized to identify regions of interest on the films and characterize the system with atomic resolution, revealing main features affected by strain on the bilayer structure. Simple models were used to probe the interrelations between STM-observed features and heterostrain in the film, indicating potential extra degrees of freedom in altering material properties.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Kalyan Biswas, Jose I. Urgel, Kun Xu, Ji Ma, Ana Sanchez-Grande, Pingo Mutombo, Aurelio Gallardo, Koen Lauwaet, Benjamin Mallada, Bruno de la Torre, Adam Matej, Jose M. Gallego, Rodolfo Miranda, Pavel Jelinek, Xinliang Feng, David Ecija
Summary: This study reported the successful synthesis of a hexabenzocoronene derivative embedded with graphitic nitrogen on the Au(111) surface using on-surface assisted cyclodehydrogenation, revealing a novel avenue for designing carbon nanostructures with dicationic properties. By introducing the concept of cationic nitrogen doping of nanographenes on surfaces, the research opens up new possibilities for the development of innovative carbon nanostructures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Crystallography
Soumya Mandal, Ashish Kumar Gupta, Braxton Hays Beavers, Vidit Singh, Jagdish Narayan, Ritesh Sachan
Summary: This study provides detailed insights into the atomic structures of heterogeneous interfaces in LSMO film grown on c-Al2O3 substrate, revealing the nucleation of periodic misfit dislocations and confirming theoretical predictions. Experimentally observed strain relaxation following misfit dislocation formation reduces residual strain, and interfacial interdiffusion within two monolayers at both interfaces was confirmed through electron energy-loss spectroscopy analysis.
Article
Chemistry, Multidisciplinary
Yujing Ma, Kazuma Sugawara, Yusuke Ishigaki, Kewei Sun, Takanori Suzuki, Shigeki Kawai
Summary: We successfully synthesized pyrrolopyrrole-bridged ladder oligomers from 11,11,12,12-tetrabromo-1,4,5,8-tetraaza-9,10-anthraquinodimethane molecules on Ag(111) using bond-resolved scanning tunneling microscopy. The non-dehydrogenative cyclization between pyrazine and ethynylene/cumulene groups has a low-activation barrier, forming dimeric oligomers containing dipyrazinopyrrolopyrrolopyrazine units and providing new insights into strain sensitivity in ladder-oligomer formation.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Dechun Zhou, Heping Li, Nan Si, Hui Li, Harald Fuchs, Tianchao Niu
Summary: 2D materials have attracted attention for their unique properties since the discovery of graphene, with monoelemental 2D materials standing out for their superior synthetic exploration, excellent mobility, and wide range of band gaps. Efforts have been devoted to fabricating high-quality materials and revealing growth mechanisms in atomic scale.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Multidisciplinary Sciences
Mohammadreza Shokouhimehr, Seyed Ali Delbari, Abbas Sabahi Namini, Ehsan Taghizadeh, Sunghoon Jung, Jin Hyuk Cho, Quyet Van Le, Joo Hwan Cha, Soo Young Kim, Ho Won Jang
Summary: A carbon-fiber (C-f) doped TiB2-SiC composite was prepared and investigated, revealing its densification behavior, micro/nanostructural properties, and mechanical characteristics. The addition of C-f resulted in the removal of surface oxide layers, transformation of TiB2 and SiC, and eventual conversion into graphite nanosheets. Nanoindentation tests showed that the hardness, elastic modulus, and stiffness values followed the order of TiB2 > SiC > TiB2/SiC interface.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Bo Gao, Yiwei Zhao, Xiaoye Du, Dan Qian, Shujiang Ding, Chunhui Xiao, Jin Wang, Zhongxiao Song, Ho Won Jang
Summary: This study reports a facile carbon doping strategy to enhance the phase transition of MoS2 and explains the counterintuitive directionality of the transitions using density functional theory calculations. The results show that the existence of carbon as interstitial atoms is more favorable to the phase transition, and the heterogeneous interfaces between 2H and 1T or 1T' are more conducive to charge transfer. The trinary-heterostructure nanofilm exhibits excellent electrocatalytic activities, providing insights into the phase transition mechanism of 2D transition metal dichalcogenides and guidance for scalable production of trinary-heterostructure electrocatalysts.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jung Hun Lee, Jaegeun Lyu, Minsong Kim, Hyungju Ahn, Soohwan Lim, Ho Won Jang, Hyun-Jong Chung, June Hyuk Lee, Jaseung Koo, Wi Hyoung Lee
Summary: Interfacial structures of TIPS-pentacene/polymer blends were investigated using neutron and X-ray reflectivity. The TIPS-pentacene/d-PMMA blends exhibited a vertically phase-separated structure with a sharp interface, while the TIPS-pentacene/d-PS blend showed intermixing near the interface. The formation of surface-segregated hexagonal spherulites of TIPS-pentacene on d-PMMA interface resulted in higher field-effect mobility compared to dendritic crystals from d-PS blends.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Seungwan Woo, Eungbeom Yeon, Rafael Jumar Chu, Jihoon Kyhm, Hoki Son, Ho Won Jang, Daehwan Jung, Won Jun Choi
Summary: Epitaxial growth of bulk InAs1-xSbx layer on GaAs substrate is a promising method for cost-effective long-wavelength infrared sensors. This study focuses on the analysis of metamorphic InAsSb layers grown on an InAs/GaAs virtual substrate with optimized growth conditions and group-V flux control. The research reveals that increasing Sb composition leads to significant surface roughening, but lowering the growth temperature mitigates this while allowing strain relaxation. Furthermore, a high Sb composition also results in a dramatic increase in threading dislocation density. The narrow energy bandgap achieved in the InAs0.42Sb0.58 layer demonstrates its potential for long-wavelength infrared optoelectronics applications.
APPLIED SURFACE SCIENCE
(2023)
Review
Chemistry, Physical
Yujin Kim, Sang Eon Jun, Goeun Lee, Seunghoon Nam, Ho Won Jang, Sun Hwa Park, Ki Chang Kwon
Summary: Green hydrogen, created by water splitting with renewable electricity, is regarded as a next-generation sustainable energy source. Electrodeposition, with its advantages of being environmentally friendly and economically advantageous, is widely used to prepare electrocatalysts for highly efficient water-splitting systems. However, there are still challenges in depositing uniform and large numbers of catalytic active sites. This review article focuses on recent advancements in electrodeposition for water splitting and discusses strategies to address current issues, as well as highly catalytic electrodeposited catalyst systems.
Review
Chemistry, Physical
Goeun Lee, Sang Eon Jun, Yujin Kim, In-Hyeok Park, Ho Won Jang, Sun Hwa Park, Ki Chang Kwon
Summary: Developing cost-effective, highly catalytic active, and stable electrocatalysts in alkaline electrolytes is crucial for efficient anion-exchange membrane water electrolysis (AEMWE). Metal oxides/hydroxides have emerged as promising electrocatalysts for water splitting due to their abundance and tunable electronic properties. However, achieving efficient catalytic performance with single metal oxide/hydroxide-based electrocatalysts is challenging. This review focuses on advanced strategies such as nanostructure engineering, heterointerface engineering, single-atom catalysts, and chemical modification to synthesize multicomponent metal oxide/hydroxide-based materials. The challenges and future prospects of these electrocatalysts are discussed.
Article
Materials Science, Multidisciplinary
Chung Won Lee, Sang Eon Jun, Seung Ju Kim, Tae Hyung Lee, Sol A. Lee, Jin Wook Yang, Jin Hyuk Cho, Shinyoung Choi, Cheol-joo Kim, Soo Young Kim, Ho Won Jang
Summary: Continuous monitoring of taste-inducing ions and molecules in liquids is crucial for the development of electronic tongues (E-tongues). This study focuses on the highly selective and sensitive real-time detection of Na+ due to its importance in determining the saltiness of food. The researchers designed a graphene-based channel decorated with Calix[4]arene and Nafion, which act as a receptor and a molecular sieve respectively, to enhance selectivity and sensitivity and prolong the device's lifespan. By combining the device with a microfluidic channel, dynamic on-off functions were achieved. The device exhibits highly selective and sensitive Na+ detection properties compared to other molecules/ionic species and has a lifespan of at least 220 days. It can also accurately distinguish real beverages containing Na+, as demonstrated by principal component analysis. These findings suggest that the device has the potential to become a platform for E-tongues in the future.
Article
Materials Science, Multidisciplinary
Soo Young Jung, Hyung-Jin Choi, Jun Young Lee, Min-Seok Kim, Ruiguang Ning, Dong-Hun Han, Seong Keun Kim, Sung Ok Won, June Hyuk Lee, Ji-Soo Jang, Ho Won Jang, Seung-Hyub Baek
Summary: Epitaxial buffer layers such as ceria (CeO2)/yttria-stabilized zirconia (YSZ) allow direct integration of oxide single crystal thin films on silicon (Si). This study investigated the evolution of microcracks in sputter-grown epitaxial CeO2 layers by varying the sputtering power and thickness of CeO2 thin films on different substrates. The results showed that increasing the sputtering power resulted in more compressive strain in the CeO2 thin films, which suppressed the evolution of microcracks.
ELECTRONIC MATERIALS LETTERS
(2023)
Article
Chemistry, Analytical
Seonyong Lee, Sungkyun Choi, Sung Hyuk Park, Sung Hwan Cho, Woonbae Sohn, Tae Hoon Eom, Yeonhoo Kim, Ho Won Jang
Summary: Hematite is a promising gas sensing material for volatile organic compounds due to its adjustable semiconducting properties and abundant reserves. Directly grown hematite nanorods on patterned SiO2/Si substrate were achieved using a facile hydrothermal method, demonstrating rapid response time and enhanced sensitivity and selectivity to acetone when decorated with Au nanoparticles. Overall, this synthesis-in-place hydrothermal method expands the potential for fabricating high-performance gas sensors with various nanostructured metal oxides.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Physical
Byungsoo Kim, Seungju Kim, Tae Hyung Lee, Duyoung Yang, Dongyup Lee, Woonbae Sohn, Euijoon Yoon, Yongjo Park, Ho Won Jang
Summary: This study achieved highly enhanced photoelectrical performance of UVC PDs by implementing single-domain epitaxy on a hexagonal sapphire substrate. The 2D beta-Ga2O3 films exhibited a smooth surface and low concentration of point defects, enabling efficient charge separation. Additionally, a tailored anti-reflection coating was adopted to improve charge generation.
Article
Chemistry, Physical
Mi Gyoung Lee, Jin Wook Yang, Ik Jae Park, Tae Hyung Lee, Hoonkee Park, Woo Seok Cheon, Sol A. Lee, Hyungsoo Lee, Su Geun Ji, Jun Min Suh, Jooho Moon, Jin Young Kim, Ho Won Jang
Summary: The introduction of indium oxide nanorods as an electron transport layer enhances the photoelectrochemical performance of bismuth vanadate. A tannin-nickel-iron complex is used as an oxygen evolution catalyst to accelerate the reaction kinetics. The fabricated TANF/BiVO4/In2O3 NR photoanode exhibits improved photoactivity with high photocurrent densities.
Article
Chemistry, Analytical
Tae Hoon Eom, Sang Eun Lee, Yeong Jae Kim, Sungkyun Choi, Gi Baek Nam, Jung-El Ryu, Tae Hyung Lee, Jin Wook Yang, Sung Hwan Cho, Seung Ju Kim, Sang Eon Jun, Seonyong Lee, Seungsoo Kim, Hee Jung Park, Ho Won Jang
Summary: Chemoresistive humidity sensors based on ultrathin V2O5•nH2O nanobelts show promising performance in real-time breath monitoring, with rapid response and recovery, as well as excellent selectivity to humidity.
SENSORS AND ACTUATORS B-CHEMICAL
(2024)
Article
Nanoscience & Nanotechnology
Eungbeom Yeon, Seungwan Woo, Rafael Jumar Chu, In-Hwan Lee, Ho Won Jang, Daehwan Jung, Won Jun Choi
Summary: Monolithic integration of GaSb-based optoelectronic devices on Si is a promising approach for achieving a low-cost, compact, and scalable infrared photonics platform. Using appropriate defect filter layers can reduce dislocation densities and improve performance.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Review
Chemistry, Physical
Sang Eon Jun, Jae Kwan Lee, Ho Won Jang
Summary: This review summarizes the superiorities and utilizations of 2D materials for photoelectrochemical water splitting including transition metal dichalcogenides, graphene, graphdiyne, black phosphorus, layered double hydroxides, g-C3N4, and MXenes.
Review
Chemistry, Physical
Soo Min Lee, Woo Seok Cheon, Mi Gyoung Lee, Ho Won Jang
Summary: This article discusses the principles and recent progress of EC CO2RR, with a focus on the influence of coordination environments of single-atom catalysts on the catalytic ability and active site stability of CO2RR.
